Nanoparticles and cancer therapy

A team of University of Texas at Arlington researchers have
developed a method that uses magnetic carbon nanoparticles to target and
destroy cancer cells through laser therapy - a treatment they believe could be
effective in cases of skin and other cancers without damaging surrounding
healthy cells.

Cancer cells before (a) and after (b) magnetic field assisted photothermal destruction using cw near-infrared laser beam. Live cells are stained green and dead cells are stained red.

A paper about the work by Ali R.
Koymen, professor of physics, and Samarendra Mohanty, assistant professor of
physics, was published in January’s edition of the Journal
of Biomedical Optics.

Ling Gu and Vijayalakshmi Vardarajan, two
post-doctoral researchers in Mohanty’s lab, were coauthors on the paper
“Magnetic-field-assisted photothermal therapy of cancer cells using Fe-doped
carbon nanoparticles.”

“Because these nanoparticles are
magnetic, we can use an external magnetic field to focus them on the cancer
cells. Then, we use a low-power laser to heat them and destroy the cells
beneath,” Koymen said. “Since only the carbon nanoparticles are affected by the
laser, the method leaves the healthy tissue unharmed and it is non-toxic.”

Koymen, Mohanty and R.P.
Chaudhary, a student in the UT Arlington College of Engineering, developed a
way of creating nanoparticles using an electric plasma discharge inside a
benzene solution. A paper on that discovery was published in December in the Journal of Nanoscience and Nanotechnology.

Carbon nanoparticles produced
for the cancer study varied from five to 10 nanometers wide. A human hair is
about 100,000 nanometers wide.

Mohanty said the carbon
nanoparticles can be coated to make them attach to cancer cells once they are
positioned in an organ by the magnetic field. He said the new method has
several advantages over current technology and could be administered using
fiber optics inside the body.

“By using the magnetic field, we
can make sure the carbon nanonparticles are not excreted until the
near-infrared laser irradiation is finished. They are also crystalline and smaller than carbon nanotubes, which makes
for less cell toxicity,” he said.

The magnetic carbon
nanoparticles also are fluorescent. So they can be used to enhance contrast of
optical imaging of tumors along with that of MRI, Mohanty said.

Mohanty said lab tests also
showed that the carbon nanoparticles and a cw (continuous wave) near-infrared
laser beam could be used to put a hole in the cell, revealing another potential
medical use.

“Without killing the cell we can heat it up a
little bit and deliver drugs and genes to the cell using low power cw near-infrared
laser beam. This is an additional important novelty of our photothermal
approach with carbon nanoparticles,” he said.

Koymen and Mohanty are seeking
funding from the National Institutes of Health to continue this work. Their
research is an example of the groundbreaking work going on at UT Arlington, a
comprehensive research institution of 33,439 students in the heart of North
Texas. Visit www.uta.edu to
learn more.